"Windows is indeed slower than other operating systems in many scenarios, and the gap is worsening." That's one way to start an insider explanation of why Windows' performance isn't up to snuff. Written by someone who actually contributes code to the Windows NT kernel, the comment on Hacker News, later deleted but reposted with permission on Marc Bevand's blog, paints a very dreary picture of the state of Windows development. The root issue? Think of how Linux is developed, and you'll know the answer.

No, I know it's fast and so is Windows. Which one is "faster"? I don't know and I don't care. On any reasonably modern computer both are fast enough.

Facts mate... facts. The truth will set you free.

You didn't really provide any but here's my personal experience:
I have run Ubuntu 12.10 on a old laptop with a crummy Intel gm855 video card and only 768Mb RAM and it was perfectly usable. GUI operations did certainly not take minutes. I also have it on a 2Ghz dual-core with Intel HD graphics and 4Gb RAM and it's just as fast as Windows. In fact, Ubuntu is a bit snappier but since the Windows is factory Lenovo the difference might not be Windows fault.